This is a note to let you know that I've just added the patch titled
io_uring/net: fix multishot accept overflow handling
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
io_uring-net-fix-multishot-accept-overflow-handling.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From a37ee9e117ef73bbc2f5c0b31911afd52d229861 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@xxxxxxxxx>
Date: Wed, 14 Feb 2024 08:23:05 -0700
Subject: io_uring/net: fix multishot accept overflow handling
From: Jens Axboe <axboe@xxxxxxxxx>
commit a37ee9e117ef73bbc2f5c0b31911afd52d229861 upstream.
If we hit CQ ring overflow when attempting to post a multishot accept
completion, we don't properly save the result or return code. This
results in losing the accepted fd value.
Instead, we return the result from the poll operation that triggered
the accept retry. This is generally POLLIN|POLLPRI|POLLRDNORM|POLLRDBAND
which is 0xc3, or 195, which looks like a valid file descriptor, but it
really has no connection to that.
Handle this like we do for other multishot completions - assign the
result, and return IOU_STOP_MULTISHOT to cancel any further completions
from this request when overflow is hit. This preserves the result, as we
should, and tells the application that the request needs to be re-armed.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 515e26961295 ("io_uring: revert "io_uring fix multishot accept ordering"")
Link: https://github.com/axboe/liburing/issues/1062
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
io_uring/net.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -1372,7 +1372,7 @@ retry:
* has already been done
*/
if (issue_flags & IO_URING_F_MULTISHOT)
- ret = IOU_ISSUE_SKIP_COMPLETE;
+ return IOU_ISSUE_SKIP_COMPLETE;
return ret;
}
if (ret == -ERESTARTSYS)
@@ -1397,7 +1397,8 @@ retry:
ret, IORING_CQE_F_MORE))
goto retry;
- return -ECANCELED;
+ io_req_set_res(req, ret, 0);
+ return IOU_STOP_MULTISHOT;
}
int io_socket_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
Patches currently in stable-queue which might be from axboe@xxxxxxxxx are
queue-6.6/io_uring-net-fix-multishot-accept-overflow-handling.patch
